a) Field of the Invention
This invention relates to deodorant and antimicrobial compositions, deodorant and antimicrobial resin compositions making use of the deodorant and antimicrobial compositions, and formed deodorant and antimicrobial resin products obtained by molding or otherwise forming the resin compositions. Described more specifically, the present invention is concerned with deodorant and antimicrobial compositions useful for imparting deodorizing power and antimicrobial activity to various base materials such as paints, synthetic fibers, synthetic resins and paper, deodorant and antimicrobial resin compositions making use of the deodorant and antimicrobial compositions, and formed deodorant and antimicrobial resin products obtained by molding or otherwise forming the resin compositions.
b) Description of the Related Art
Numerous deodorant and antimicrobial agents have been used to date in various fields. In particular, a variety of products such as films, wall paper, decorated plywood, building materials, fibers, nonwoven fabrics and clothing are required to remain free of offensive odor, bacteria, fungi and the like. If offensive odor, bacteria, fungi or the like occurs, a need often arises for its removal.
In recent years, there is an ever-increasing demand for the amenity of living space. In view of the crowding of houses due to urbanization and also of the living environment of a closed house or building structure constructed of concrete and aluminum sash windows, it has become an indispensable condition for clean-environment life that visual and olfactory unpleasant feeling and hygienically unpleasant feeling, such as microbial contamination, be removed.
Described specifically, formaldehyde-linked health disturbances have posed problems in recent years. The odor of formaldehyde has already become a social problem as xe2x80x9csick house syndromexe2x80x9d in a living environment of a closed house structure, especially in a newly-built house. This problem is attributed to formaldehyde given off from newly-developed building materials. Various productsxe2x80x94such as wall paper, decorated plywood, building materials, fibers, nonwoven fabrics, clothing, sundries and filmsxe2x80x94are hence required to have a function to remove the odor of formaldehyde given off as described above. Further, from the view point of hygine such as prevention of microbial contamination, such products are also required to be equipped with an antimicrobial and antifungal function.
An object of the present invention is, therefore, to provide a deodorant and antimicrobial composition which can impart excellent deodorizing power and antimicrobial activity to various materials.
The above-described object can be achieved by the present invention to be described subsequently herein. Namely, the present invention provides a deodorant and antimicrobial composition comprising an oxide or hydroxide of an alkaline earth metal, hydrated silica and a cationic surfactant; a deodorant and antimicrobial resin composition making use of the deodorant and antimicrobial composition, and also a formed deodorant and antimicrobial resin product obtained by molding or otherwise forming the resin composition.
The deodorant and antimicrobial composition, deodorant and antimicrobial resin composition and formed deodorant and antimicrobial resin product according to the present invention are effective for the deodorization of acetoaldehyde odor, formaldehyde odor, acetic acid odor and the like out of various offensive odors. Further, the deodorant and antimicrobial composition, deodorant and antimicrobial resin composition and formed deodorant and antimicrobial resin product according to the present invention are also excellent in antimicrobial activity.
In addition, the deodorant and antimicrobial composition, deodorant and antimicrobial resin composition and formed deodorant and antimicrobial resin product according to the present invention can impart excellent deodorizing power and antimicrobial activity to various articles.
The present invention will next be described more specifically based on preferred embodiments.
The deodorant and antimicrobial composition according to the present invention comprises, in combination, an oxide or hydroxide of an alkaline earth metal, hydrated silica, and a cationic surfactant. Illustrative of the alkaline earth metal oxide or hydroxide are the oxides and hydroxides of barium, calcium, magnesium and the like, with magnesium hydroxide being particularly effective.
This alkaline earth metal oxide or hydroxide may be used preferably in such a proportion that, when the total amount of the deodorant and antimicrobial composition is supposed to be 100 parts by weight, it amounts to 80 to 40 parts by weight. A proportion of the alkaline earth metal oxide or hydroxide smaller than the above range leads to insufficient performance in that conversion of aldehydes, especially formaldehyde into formose becomes slower. On the other hand, a proportion of the alkaline earth metal oxide or hydroxide greater than the above range also leads to insufficient performance in that the proportion of a substance adapted to undergo an addition reaction with formaldehyde for the removal of formaldehyde, that is, the cationic surfactant in the composition decreases, thereby lowering the deodorizing reaction velocity of aldehydes and resulting in insufficient fast-acting property.
The hydrated silica for use in the present invention is represented by the empirical formula SiO2 nH2O, and is in the form of secondary particles formed as a result of flocculation of fine silica particles having many silanol groups on surfaces thereof. Such hydrated silica is a flocculate of ultrafine particles of hydrated silica, which is available from a reaction of sodium silicate with a mineral acid, and contains a number of voids between particles. These voids effectively act for the adsorption of various offensive odor components such as formaldehyde.
Such hydrated silica is available, for example, from Mizusawa Industrial Chemicals, Inc., Tokyo, Japan under the trade names of xe2x80x9cP-801xe2x80x9d, xe2x80x9cP-802xe2x80x9d, xe2x80x9cP-526xe2x80x9d, xe2x80x9cP-527xe2x80x9d, xe2x80x9cP-603xe2x80x9d, xe2x80x9cP-604xe2x80x9d, xe2x80x9cP-554Axe2x80x9d, xe2x80x9cP-73xe2x80x9d, xe2x80x9cP-78Axe2x80x9d, xe2x80x9cP-78Dxe2x80x9d, xe2x80x9cP-78Fxe2x80x9d, xe2x80x9cP-707xe2x80x9d, xe2x80x9cP-740xe2x80x9d, xe2x80x9cP-752xe2x80x9d, xe2x80x9cP-50xe2x80x9d, xe2x80x9cP-766xe2x80x9d, xe2x80x9cC-1xe2x80x9d, xe2x80x9cS-0xe2x80x9d, xe2x80x9cNP-8xe2x80x9d, xe2x80x9cP-802Yxe2x80x9d, xe2x80x9cP-832xe2x80x9d, xe2x80x9cP-87xe2x80x9d, xe2x80x9cP-363xe2x80x9d, xe2x80x9cC-002xe2x80x9d, xe2x80x9cC-402xe2x80x9d and xe2x80x9cC-484xe2x80x9d, all of which are usable in the present invention.
The above-described hydrated silica may be used preferably in such a proportion that, when the total amount of the deodorant and antimicrobial composition is supposed to be 100 parts by weight, it amounts to 50 to 10 parts by weight. A proportion of the hydrated silica smaller than the above range leads to insufficient performance in that the deodorizing reaction velocity of aldehydes becomes slower, resulting in insufficient fast-acting property. On the other hand, a proportion of the hydrated silica greater than the above range also leads to insufficient performance in that, when the deodorant and antimicrobial composition according to the present invention is kneaded with a resin, the flowability of the resin is rendered poor.
As the cationic surfactant for use in the present invention, one represented by the empirical formula HOxe2x80x94Rxe2x80x94NHCH2CH2OH in which R is a C12-C14 alkylene group is preferred. The cationic surfactant reacts with an aldehyde group of formaldehyde or the like, thereby converting such an aldehyde compound into an odorless compound. Such cationic surfactants are available from Miyoshi Oil and Fat Co., Ltd., Tokyo, Japan under the trade names of xe2x80x9cMiyocol 368Exe2x80x9d xe2x80x9cMiyocol QX-33Nxe2x80x9d, xe2x80x9cDuspar 125Bxe2x80x9d, xe2x80x9cDuspar 125BNxe2x80x9d, xe2x80x9cDuspar 125BSxe2x80x9d and xe2x80x9cDuspar 1400Bxe2x80x9d, all of which are usable in the present invention.
The above-described cationic surfactants can be used either singly or in combination. They, however, include some compounds which, when mixed to produce deodorant and antimicrobial compositions, may not be sufficient in dispersibility, stability, thermal stability, light fastness, processability and/or the like. Upon using the deodorant and antimicrobial composition of this invention for various applications, heat resistance is also important in connection with processability. From this viewpoint, xe2x80x9cDuspar 125Bxe2x80x9d and xe2x80x9cDuspar 125BNxe2x80x9d are particularly preferred.
The above-described cationic surfactant may be used preferably in such a proportion that, when the total amount of the deodorant and antimicrobial composition is supposed to be 100 parts by weight, it amounts to 0.1 to 30 parts by weight. If the cationic surfactant is used in a proportion smaller than the above range, the resulting composition is insufficient in performance in that the velocity of deodorizing reaction with aldehydes becomes slower and the antimicrobial activity is insufficient. If the cationic surfactant is used in a proportion greater than the above range, on the other hand, the resulting composition itself is no longer provided with powdery property and its handling is deteriorated.
The deodorant and antimicrobial composition which comprises such components as described above can be obtained by simply mixing the individual components together, and can be used for various applications like conventional deodorant and antimicrobial agents.
When it is desired to impart deodorizing power and antimicrobial activity to a variety of formed resin products by using the above-described deodorant and antimicrobial composition of the present invention, the deodorant and antimicrobial composition can be mixed with resins into deodorant and antimicrobial resin compositions.
Examples of the resin for use in the present invention can include synthetic or modified thermoplastic resins, for example, polyolefin resins such as polyethylene and polypropylene, polyvinyl chloride, vinylon, polystyrene, polyamides, polyesters, and cellulose acetate, which have been used for manyvyears in various molded or otherwise formed products, for example, formolding or otherwise forming plastic films, plastic sheets, plastic containers, fibers and the like. These thermoplastic resins are all readily available from the market for use in the present invention, and may be either in a solid form or in a liquid form such as a paste form.
The deodorant and antimicrobial resin composition according to the present invention comprises, as essential components, two components, that is, the above-described resin and the above-described deodorant and antimicrobial composition. As their mixing ratio, 99.9 to 50 parts by weight of the resin and 0.1 to 50 parts by weight of the deodorant and antimicrobial composition, preferably 99.0 to 80 parts by weight of the resin and 1.0 to 20 parts by weight of the deodorant and antimicrobial composition can be mixed. To the resin composition according to the present invention, a variety of conventionally-known other additives for resin, for example, colorants, fillers, extender pigments, plasticizers, stabilizers, ultraviolet absorbers and the like can be added optionally as needed.
The deodorant and antimicrobial resin composition according to the present invention can be obtained by simply mixing the above-described components together or by further melting, kneading and granulating the mixture into pellets or the like. It can also be in the form of a master batch which contains a deodorant and antimicrobial component at such a high concentration (for example, a concentration of from 10 to 50 wt. %) as permitting subsequent dilution with natural (i.e., additive-free) thermoplastic-resin.
The above-described deodorant and antimicrobial resin composition is useful for the production of a formed deodorant ,and antimicrobial resin product. Examples of the formed deodorant and antimicrobial resin product of the present invention can include those obtained by molding or otherwise forming the deodorant and antimicrobial resin composition into various shapes, for example, wrapping materials made of plastic films or sheets and containers of desired shapes obtained by molding or otherwise forming the deodorant and antimicrobial resin composition by various processes.
The forming or molding of such films, sheets, containers or the like can be performed by a conventionally-known inflation extruder, press, calender, extruder, spinning machine, blow molding machine, injection molding machine, vacuum forming machine or the like by using conventionally-known various conditions as are, so that the formed deodorant and antimicrobial resin product according to the present invention can be obtained with ease.